Please do not flatten out classpath fileset or provide additional fileset

[Vampire]

With JarBundler I was able to define a fileset as child element that was unchanged put to Contents/Java/.
With AppBundler there is no such possibility besides doing it manually afterwards.
When setting up the classpath fileset like the fileset in JarBundler, all files get flattened out and put at top-level which is not working for us.
This would only work properly if you have only JAR entries in that fileset.